Tiazac (Diltiazem Hydrochloride Extended Release) – Comprehensive Product Description

Tiazac (Diltiazem Extended Release) is a calcium channel blocker used to treat high blood pressure, angina, and certain heart rhythm disorders. It works by relaxing blood vessels and improving blood flow. Tiazac helps reduce the risk of stroke and heart attack. Available as extended-release capsules from EZ Chemist.

Product Name
Tiazac

Active Ingredient
Diltiazem Hydrochloride (Extended Release)

Other Common and Brand Names
Generic Name: Diltiazem ER

Brand Names: Tiazac, Cardizem CD, Cartia XT, Dilt-XR

Drug Class: Calcium Channel Blocker – Non-Dihydropyridine

ATC Code: C08DB01

Mode of Action
Tiazac contains diltiazem, a non-dihydropyridine calcium channel blocker that inhibits calcium ion influx through L-type calcium channels in vascular smooth muscle and cardiac muscle. This results in:

Vasodilation: Reduced peripheral resistance and blood pressure

Reduced myocardial oxygen demand: Helpful in angina

Slower AV conduction and heart rate: Beneficial in arrhythmias

Indications / Uses
Tiazac is indicated for the treatment of:

Hypertension (High Blood Pressure)

Chronic Stable Angina (Exertional Angina)

Angina due to Coronary Artery Spasm (Prinzmetal’s Angina)

Rate control in Atrial Fibrillation or Supraventricular Tachycardia (off-label)

Long-term use of Tiazac reduces the risk of stroke, heart attack, and kidney complications in hypertensive patients.

Dosage and Administration
General Dosage Guidelines
Initial Dose: 120 to 240 mg once daily

Maintenance Dose: 180 to 540 mg once daily

Maximum Dose: 540 mg per day

For Hypertension
Begin with 180–240 mg once daily, adjust as needed based on BP response

Dosage may be titrated at intervals of 7–14 days

For Angina
Start with 120 mg to 180 mg once daily

Increase gradually up to 540 mg daily if required

Administration:

Take orally once daily

Swallow whole (do not crush or chew)

Can be taken with or without food

Available Forms on EZ Chemist:

Tiazac Extended Release Capsules: 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg

Order Tiazac Online from EZ Chemist

Pharmacokinetics
Bioavailability: ~40% (due to first-pass metabolism)

Onset: 2–3 hours (ER)

Peak effect: 6–11 hours

Half-life: 3–9 hours (sustained with ER form)

Metabolism: Hepatic (CYP3A4)

Excretion: Urine and feces

Safety Information
Use in Pregnancy and Lactation
Pregnancy Category C: Use only if clearly needed

Breastfeeding: Excreted in breast milk; use with caution

Pediatric Use
Safety and effectiveness not established in children

Elderly
More sensitive to effects; monitor closely for bradycardia and hypotension

Side Effects
Common Side Effects
Headache

Dizziness or light-headedness

Fatigue

Edema (swelling of ankles/feet)

Flushing

Bradycardia

Serious Side Effects
Heart block

Worsening heart failure symptoms

Severe hypotension

Liver enzyme elevation

Allergic reactions (rash, pruritus)

Monitor ECG, liver function, and blood pressure regularly during long-term therapy.

Warnings and Precautions
Do not use in sick sinus syndrome or AV block (unless pacemaker is present)

Avoid in patients with decompensated heart failure

Caution in hepatic impairment – diltiazem is extensively metabolized in the liver

Abrupt withdrawal may worsen angina or cause rebound hypertension

Use cautiously with beta-blockers, which may increase bradycardia risk

Drug Interactions
Interacting Drug/Class Effect Clinical Consideration
Beta-blockers (e.g., metoprolol) Enhanced bradycardia and AV block Monitor HR and BP
CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) Increased diltiazem levels Risk of toxicity
CYP3A4 inducers (e.g., rifampin, phenytoin) Reduced diltiazem efficacy Monitor and adjust dose
Statins (simvastatin, lovastatin) Increased risk of myopathy Limit simvastatin to 10 mg/day
Digoxin Increased digoxin levels Monitor digoxin serum levels

Source: FDA label, DrugBank, J Clin Pharmacol 2003; Stambler B, et al. Am J Cardiol 1996.

Drug Classification
Pharmacologic Class: Calcium Channel Blocker

Therapeutic Class: Antihypertensive, Antianginal, Antiarrhythmic (off-label)

Legal Category: Prescription-only (Rx)

Storage Instructions
Store at 20–25°C (68–77°F)

Keep in original container, away from moisture

Keep out of reach of children

Frequently Asked Questions (FAQs)
What is Tiazac used for?
Tiazac is used to treat high blood pressure, chest pain (angina), and certain heart rhythm disorders. It helps reduce the workload on the heart and lowers the risk of cardiovascular events.

How should I take Tiazac?
Take Tiazac once daily at the same time. Swallow the capsule whole without chewing or crushing.

Can I take Tiazac with food?
Yes, Tiazac can be taken with or without food. However, take it consistently in the same manner each day.

Is Tiazac a beta-blocker?
No. Tiazac is a calcium channel blocker, not a beta-blocker, but it may have similar heart rate-lowering effects.

Is it safe to take Tiazac with other heart medications?
Tiazac may interact with beta-blockers, digoxin, and certain statins. Always consult your doctor for drug interaction assessment.

What if I miss a dose?
Take the missed dose as soon as you remember. If it’s near the time of the next dose, skip the missed one. Do not double the dose.